4 General and operational requirements
4.1 Introduction
Requirements contained in this clause 4 are requirements not taken up in other clauses and which cannot be verified by repeatable methods of measurement.
These requirements include the applicable general and operational requirements of IEC 60945.
The manufacturer shall declare compliance with these requirements and shall provide relevant documentation. The declarations, documentation and where necessary, the EUT shall be checked.
The manufacturer shall also declare the composition of the EUT and the category for durability and resistance to environmental conditions specified in IEC 60945 for each unit of the EUT.
4.2 Required functions and their availability
At night, night vision equipment should be capable of detecting objects above the water surface within a certain distance from one's own craft, and of displaying the information pictorially in real time, to assist in collision avoidance and safe navigation.
4.3 Continuous operation
Night vision equipment on board HSC, while navigating at sea, should be capable of continuous operation from after sunset until before sunrise. After the equipment has been switched on it should be operational in less than 15 minutes.
4.4 Field of view
The required horizontal field of view should be at least 20°, i.e. 10°on either side of the bow. The vertical field of view should be at least 12°and should be sufficient to enable the equipment to fulfil the performance requirements of this standard as well as being able to see the horizon.
Optionally other fields of view may be provided. Their selection should be made with a non-locking switch, which returns to the required field of view when released.
4.5 Pan range of the field of view
The axis of the field of view should be capable of being moved at least 20｡?orizontally to either side, as required in resolution A. 694 (17).
4.6 Pan speed of the field of view
By activation of a single control element, the axis of the field of view should be capable of being returned automatically to the ahead position at a minimum angular speed of 30 %.The system should be capable of panning at a minimum angular speed of 30°/s.
4.7 Vertical trim of the field of view
The elevation of the field of view should be capable of being adjusted of at least 10｡?o compensate for the trim of the vessel.
